Locate carbon, denoted by the letter C, in the periodic table. It is located in period 4A, Row 2.
Identify the atomic number and mass number of carbon. The atomic number, located above the C symbol, is 6 and denotes the number of protons in the element. The mass number, located directly below the C symbol, is 12.001 and gives the number of nucleons in the element.
Round the mass number to the nearest whole number. Rounding 12.001 to the nearest whole number gives carbon a mass number of approximately 12.
Subtract the atomic number from the rounded mass number to obtain the number of neutrons. Subtracting 6 from 12 identifies carbon as having 6 neutrons. Thus, carbon has 6 protons and 6 neutrons.